• Resources Recycling
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• v.16 no.5
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• pp.71-76
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• 2007

The mixed plastic waste generated from households after hand-picking and/or mechanical sorting processes amounts to 1,750,000 ton in 2006, and most of these waste are finally end up with landfill and/or incineration due to the lacks of separation technologies and economical reasons. The mixed plastic wastes can not be used as raw materials for chemical and/or thermal recycling processes because of their high content of PVC(upto 4.0 wt.%). In the present research, gravity separation system has been developed to remove PVC from the mixed plastic waste and to recover the PO-type plastics. This system mainly consists of air classification, magnetic separation, one-step crushing, feeding system at fixed rate and wet-type gravity separation system. The gravity system based on centrifugal separation has been developed at capacity of 0.5 ton/h and it consists of mixing, precleaning, separation, dewatering, recovery system and wastewater treatment system, etc. The main objective of this process is to achieve high separation efficiency of polyolefins with less than 0.3 wt.% PVC content and less than 10% moisture content in the final products. In addition, a crushing unit of with 8 rotor system is also developed to improve the crushing efficiency of soft-type plastics. The system with a capacity of 1.0 ton/h is developed and operational results are presented.

• Journal of Energy Engineering
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• v.5 no.2
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• pp.160-169
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• 1996

Parametric studies are conducted for optimizing the integration design between gas turbine compressor and air separation unit (ASU) of integrated gasification combined cycle power plant. The present study adopts the ASU of double-distillation column process, from which integration conditions with compressor such as the heat exchanger condition between air and nitrogen, the amount and the pressure of extracted air are defined and mathematically formulated. The performance variations of the compressor integrated with ASU are analyzed by combining streamline curvature method and pressure loss models, and the predicted results are compared with the performance test results of actual compressors to verify the prediction accuracy. Using the present performance prediction method, the effects of pinch-point temperature difference (PTD) in the heat exchanger, the amount and the pressure of extracted air on compressor performances are quantitatively examined. As the extraction air amount or the PTD is increased, the pressure ratio and the power consumption of compressor are increased. The compressor efficiency deteriorates as the increase of the flow rate of air extracted at higher pressure level while improving at lower pressure air extraction. Furthermore, through the characteristic curve between generalized inlet condition and efficiency of compressor, optimal integration condition is presented to maximize the compressor efficiency.

• Journal of the Korea Institute of Building Construction
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• v.24 no.3
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• pp.319-329
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• 2024

This study examined domestic and international regulations concerning concrete unit weight, along with an evaluation of unit weight in concrete poured on construction sites. Fluctuations in unit weight were observed to correlate with concrete quality issues such as material separation, bleeding, and latency. A word cloud analysis, centered on the concept of concrete quality, further highlighted the significant influence of unit weight. Comparative analysis between Korea and Japan revealed few substantial differences in unit weight management and measurement techniques. However, calculation of concrete unit weight at delivery, using the unit volume mass method, indicated considerable variability among random on-site samples. Notably, the unit weight often exceeded the recommended standard. These findings emphasize the necessity for strict adherence to unit weight standards by all stakeholders involved in concrete production and construction, including ready-mix concrete (REMICON) producers, construction firms, and inspectors. To ensure consistent quality of cast concrete on-site, the establishment of a more comprehensive and practical system is recommended, incorporating measures such as on-site inspections.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.10b
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• pp.98-103
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• 1996

석탄가스화복합발전소내 공기분리장치와 연계된 가스터빈 공기압축기의 성능병화를 예측할 수 있는 해석방법을 제안하였다. 공기분리장치와 연계된 가스터빈용 공기압축기의 성능변화는 유선곡률방법과 압력손실모델을 결합한 해석방법을 사용하였으며, 예측결과들을 실제 압축기성능 시험 결과와 비교하여 예측정확도를 검증하였다. 제안된 압축기성능 해석방법을 근간으로, 압축기와 공기분리장치의 연계조건인 열교환기의 핀치포인트 온도차, 추출공기량 및 추출 공기압력이 압축기 성능변화에 미치는 영향을 정량적으로 예측하였다. 공기추출량이 늘어나거나 핀치포인트 온도차가 커질수록, 압축기의 압축비 및 소요동력은 증가하나, 압축기 효율은 공기추출량의 증가에 따라 고압공기추출시에는 저하되고, 저압공기추출시에는 향상되었다. 더 나아가, 압축기의 일반화된 성능특성곡선의 제시를 통해, 압축기 효율을 극대화 할 수 있는 압축기/공기분리장치 간 연계조건의 최적화를 시도하였다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.45-48
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• 1999

석탄가스화복합발전(Integrated Gasification Combined Cycle)기술은 우수한 환경성능과 열성능을 지니고 있어 장래 미분탄화력을 대신할 수 있는 대체기술로서 각광을 받고 있다. IGCC는 석탄가스화, 정제, 복합발전계통 및 공기분리계통 등 그 구성요소가 복잡하여 이들간의 시스템 최적화 정도에 따라 경제성 및 플랜트 성능이 크게 좌우된다. 최근에 가스터빈과 공기분리설비(Air Separation Unit)를 연계시켜 IGCC플랜트 성능을 향상시키는 연구가 다수 진행되었다[1],[2],[3]. 본 연구에서는 가스터빈과 ASU 간의 연계시 공기추출량을 결정하는 인자들을 검토하고 Texaco quench 가스화공정을 채용한 IGCC 플랜트에 대해 GatecCyle code등 상용코드를 이용하여 모델링하고 가스터빈 압축기 공기추출량에 따른 IGCC 플랜트 성능을 분석하였다. 본 연구 결과를 통하여 대상 IGCC 플랜트의 적정 공기추출량을 결정하고 플랜트 성능을 계산하였다. 본 연구 결과는 전력연구원에서 수행중인 300MW급 IGCC 예비기본설계에 활용될 것이다.(중략)

• Journal of Ocean Engineering and Technology
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• v.2 no.2
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• pp.130-137
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• 1988

This thesis introduced that character of a treatment technique for a mading synthetic resin Hifiow-Ring. The material system of packings make an experiment air$NH_{3}$/air$H_{2}SO_{4}$, $SO_{2}$-air/NaOH, $NH_{3}$-air/$/H_{2}SO_{4}$ under general conditions. Lattices packing compared with conventional packings was proved low pressure loss and high separation efficiency for high loading per trans unit. And an inflow materal tested for absorption and rectification, it made an experiment under a range regular temperature, low energy and small amount of money. That made possible in simple equation, volume material tranfer coefficient$\beta_{L}$ . a by absorption or $\beta_{V}$ .a calculated in all range loading. The peculiarity pressure loss $\Delta\;P/NUT_{ov}$ for Hiflow-ring contributed to a fall cost of energy, a grade number of a vacuum rectification and absorption calculation.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.571-580
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• 2016

In this paper, performance of the gas turbine combined cycle(GTCC) using pre-combustion carbon capture technology was comparatively analysed. Steam reforming and autothermal reforming were used. In the latter, two different methods were adopted to supply oxygen for the reforming process. One is to extract air form gas turbine compressor (air blowing) and the other is to supply oxygen directly from air separation unit ($O_2$ blowing). To separate $CO_2$ from the reformed gas, the chemical absorption system using MEA solution was used. The net cycle efficiency of the system adopting $O_2$ blown autothermal reforming was higher than the other two systems. The system using air blown autothermal reforming exhibited the largest net cycle power output. In addition to the performance analysis, the influence of fuel reforming and carbon capture on the operating condition of the gas turbine and the necessity of turbine re-design were investigated.

• Journal of The Korea Institute of Healthcare Architecture
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• v.24 no.3
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• pp.49-57
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• 2018

Purpose: The increase in patients requiring hemodialysis has resulted in an increase dialysis-associated infections risk. but there are no Renal Dialysis unit design standard meet specified safety and quality standards. Therefore, appropriate Establish standards and legal regulation is important for the provision of initial certification and maintenance of facility, equipment, and human resource quality. Methods: Literature survey on the design guideline and standards of Renal Dialysis unit design in Korea, U.S, Germany, Singapore, Hongkong, Dubai. Results: There are no established standards for facilities in dialysis units in Korea. To prevent infections in dialysis patients, necessary establish standards. Considering the domestic and overseas Health-care facilities standards, the major factors to be considered in the medical environment for Renal Dialysis Unit are as follows. First, planning to separate Clean areas(treatment area) from contaminated areas(medical waste storage area). Second, ensure sufficient space and minimum separation distance. Although there may be differences depending on the circumstances of individual institutions, renal dialysis unit consider the space to prevent droplet transmission. Third, secure infrastructure of infection prevention such as sufficient amount of hand hygiene sinks. Hand washing facilities for staff within the Unit should be readily available. Hand hygiene sinks should be located to prevent water from splashing into the treatment area. Fourth, Heating, ventilation and air conditioning (HVAC) system for Renal Dialysis Unit is all about providing a safer environment for patients and staff. Implications: The results of this paper can be the basic data for the design of the Renal Dialysis Units and relevant regulations.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.209-214
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• 1998

A thermodynamic simulation method is developed for the process design and the performance evaluation of the gas turbine in IGCC power plant. The present study adopts four clean coal gases derived from four different coal gasification and gas clean-up processes as IGCC gas turbine fuel, and considers the integration design condition of the gas turbine with ASU(Air Separation Unit). In addition, the present simulation method includes compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. The present prediction results show that the efficiency and the net power of the IGCC gas turbines are seperior to those of the natural gas fired one but they are decreased with the air extraction from gas turbine to ASU. The operation point of the IGCC gas turbine compressor is shifted to the higher pressure ratio condition far from the design point by reducing the air extraction ratio. The exhaust gas of the IGCC gas turbine has more abundant wast heat for the heat recovery steam generator than that of the natural gas fired gas turbine.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.7-14
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• 1999

This simulation method is developed by using GateCycle code for the performance evaluation of the gas turbine in IGCC(Integrated Gasification Combined Cycle) power plant that uses clean coal gas fuel derived from coal gasification and gas clean-up processes and it is integrated with ASU(Air Separation Unit). In the present simulation method, thermodynamic calculation procedure is incorporated with compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. With the clean coal gases produced through commercially available chemical processes, their compatibility as IGCC gas turbine fuel is investigated in the aspects the overall performance of the gas turbine system. The predictions by the present method show that the reduction of the air extraction from gas turbine to ASU results in a remarkable increase in the efficiency and net power of gas turbines, but it is accompanied with a shift of compressor operation point toward to surge limit. In addition, the present analysis results reveal the influence of compressor performance characteristics of gas turbine have to be carefully examined in designing the ASU integration process and evaluating the overall performance parameters of the gas turbine in IGCC Power plant.